JP7307741B2 - Curable low-sulfur liquid rubber composition and method for producing the same - Google Patents

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of US Patent Application No. 15/935,262, filed March 26, 2018, the entire contents of which are hereby incorporated by reference.

FIELD OF THE INVENTION Aspects of the present invention are directed to curable low-sulfur liquid rubber compositions, and in particular, peroxide-based curable low-sulfur liquid rubber compositions and methods of making the same.

Liquid rubber compositions are commonly used in the automotive industry as adhesives, sealants, and/or sound dampening materials. Such compositions are called "liquid rubber compositions" because they contain one or more polymers that are liquid at room temperature (25°C) but can be cured by a crosslinking reaction to provide a solid elastomeric composition. Various types of liquid rubber compositions can be used, depending on the intended purpose of the liquid rubber composition. The cross-linking agent for these compositions is generally sulfur or sulfur compounds. In automotive body shops and paint shops, these liquid rubber compositions are usually cured at temperatures ranging from 145°C to 190°C. However, methods of curing liquid rubber compositions at temperatures between 145°C and 190°C have adverse environmental impacts.

Accordingly, improved liquid rubber compositions that reduce adverse environmental impacts are highly desirable.

Aspects of the present invention relate to curable low-sulfur liquid rubber compositions, and particularly to peroxide-based curable low-sulfur liquid rubber compositions and methods of making the same. The inventors have found that by using a peroxide system comprising at least one organic peroxide with a 10-hour decomposition half-life temperature of 60°C to 100°C, without the use of appreciable amounts of sulfur, have found that it is possible to effectively cure compositions based on one or more liquid polymers containing vinyl groups at relatively low temperatures (eg, 100° C. to 140° C.).

Various exemplary aspects of the invention can be summarized as follows.
Embodiment 1: A polymer comprising in polymerized form at least one monomer having a carbon chain of 4 carbon atoms, said polymer having a vinyl content of 1% to 90% and a vinyl content of 800 g/mol to 15,000 g/mol a polymer having a number average molecular weight;
a peroxide system comprising at least one organic peroxide having a 10 hour decomposition half-life temperature of 60°C to 100°C;
A curable low-sulfur liquid rubber composition comprising
A composition, wherein said composition has a sulfur content of 0-1% by weight and is curable at a temperature of 100°C to 140°C.

Aspect 2: The composition of aspect 1, wherein the polymer comprises butadiene in polymerized form.

Aspect 3: The composition of aspect 1, wherein the polymer comprises butadiene and styrene in polymerized form.

Aspect 4: The composition of aspect 1, wherein the polymer comprises at least one of liquid polybutadiene and liquid styrene-butadiene copolymer and has a 1,2-vinyl content of at least 10%.

Aspect 5: The composition of aspect 1, wherein said at least one peroxide is selected from the group consisting of peroxyketals, diacyl peroxides, and peroxyesters.

Aspect 6: The composition of aspect 1, wherein said peroxide system comprises at least two organic peroxides.

Aspect 7: The composition of aspect 6, wherein said at least two organic peroxides are selected from the group consisting of peroxyketals, diacyl peroxides, and peroxyesters.

Embodiment 8: The at least two peroxides are 1,1′-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1′-di(tert-butylperoxy)-cyclohexane, and A composition according to aspect 6, selected from the group consisting of dibenzoyl peroxide.

Aspect 9: The composition according to aspect 1, wherein said composition further comprises from 0.5% to 15% by weight of at least one auxiliary agent, other than sulfur or a sulfur compound, suitable for crosslinking.

Aspect 10: The composition of aspect 9, wherein said at least one coagent is selected from the group consisting of acrylates, methacrylates, bismaleimides, vinyl esters, allyl compounds, and derivatives thereof.

Aspect 11: The composition of aspect 1, wherein said composition is curable at a temperature of 110°C to 140°C.

Aspect 12: The composition of aspect 11, wherein said composition is curable at a temperature of 120°C to 140°C.

Aspect 13: The composition of aspect 1, wherein said composition further comprises additives or auxiliaries suitable for accelerating curing of said composition.

Aspect 14: The composition of aspect 1, wherein said composition is free of mineral or aromatic oils.

Aspect 15: A crosslinked low sulfur rubber comprising the composition of aspect 1 cured at a temperature of 100°C to 140°C.

Aspect 16: The cured crosslinked low sulfur rubber uses an effective amount of sulfur or sulfur compounds to provide a sulfur content of greater than 1% by weight than similar crosslinked sulfur rubbers cured without a peroxide system. 16. The crosslinked low sulfur rubber of aspect 15, having a torsional shear differential of at least 2.0 dNm.

Aspect 17: Curing the curable low sulfur liquid rubber composition of Aspect 1 by heating;
wherein the curable low sulfur liquid rubber composition is curable at a temperature of 100° C. to 140° C. and contains 0 to 1 wt. How to have quantity.

Embodiment 18: Polymerizing at least one monomer having a carbon chain of 4 carbon atoms to produce a polymer having a vinyl content of 1% to 90% and a number average molecular weight of 800 g/mol to 15,000 g/mol and preparing a curable low sulfur liquid rubber composition based on the resulting polymer and peroxide system;
wherein the peroxide system comprises at least one organic peroxide having a 10-hour decomposition half-life temperature of 60°C to 100°C, wherein Said curable low sulfur liquid rubber composition is curable at a temperature of 100° C. to 140° C. and has a sulfur content of 0 to 1% by weight.

The invention is best understood from the following detailed description read in conjunction with the accompanying drawings. Drawings include the following figures:
FIG. 1 is a graph showing kinetic curves of various rubber resins during vulcanization at 160°C. Figure 2 is a graph showing kinetic curves of various rubber resins during vulcanization at 140°C. FIG. 3 is a graph showing kinetic curves of a liquid rubber composition comprising Ricon® 131 under curing with a vulcanization system or various peroxide systems according to embodiments of the present invention. FIG. 4 is a graph showing kinetic curves for liquid rubber compositions containing Ricon® 156 based on cure with a vulcanization system or a peroxide system according to embodiments of the present invention. FIG. 5 is a graph showing kinetic curves of liquid rubber compositions containing Ricon® 142 based on curing with a vulcanization system or various peroxide systems according to embodiments of the present invention. FIG. 6 is a graph showing kinetic curves of liquid rubber compositions comprising Ricon® 150 or Ricon® 100 based on curing with vulcanization systems or various peroxide systems according to embodiments of the present invention; is.

Aspects of the present invention relate to peroxide-based curable low-sulfur liquid rubber compositions and methods of making the same. Curable low sulfur liquid rubber compositions are well suited for use as adhesives, sealants, and/or sound dampening applications. By using embodiments of the present invention, curable low sulfur rubber compositions curable at temperatures between 100°C and 150°C can be obtained, which are cured at typical temperatures between 150°C and 190°C. Reduce and/or minimize adverse environmental impacts related to Further, the curable low sulfur liquid rubber composition minimizes sulfur content with greatly reduced amounts of crosslinker and/or accelerator (e.g., the sulfur content of the formulation is 1.0 wt. %) can be cured.

According to one aspect of the invention, a curable low sulfur liquid rubber composition is provided comprising at least one polymer and a peroxide system. The polymer is produced from at least one monomer having a carbon chain of 4 carbon atoms. According to a preferred embodiment, the polymer is liquid at 25°C. The polymer can include butadiene monomers, styrene monomers, and/or other diene monomers in polymerized form. For example, the polymer may be a butadiene homopolymer (polybutadiene) or a copolymer of butadiene and styrene monomers. The polymer may have a vinyl content of 1% to 90% or, for example, % vinyl content. In one embodiment, the polymer comprises at least one of liquid polybutadiene and liquid styrene-butadiene copolymer, wherein the polymer has a 1,2-vinyl content of at least 10%. Additionally, the polymer can have a number average molecular weight (determined by gel permeation chromatography) from 800 g/mol to 15,000 g/mol. Preferably, the number average molecular weight of the polymer is between 1000 g/mol and 10,000 g/mol. A combination of two or more different polymers having one or more of the above properties may be utilized in the curable low sulfur liquid rubber composition.

A curable low sulfur liquid rubber composition includes a peroxide system. By selecting specific peroxides or combinations of organic peroxides, the sulfur content (e.g., sulfur content of 1% or less) and the amount of crosslinker can be reduced while advantageously having increased crosslink density. It has been discovered that a cured rubber composition can be obtained with a reduction. The peroxide system comprises at least one organic peroxide having a 10 hour decomposition half-life temperature of 60°C to 100°C. Table 1 provides a list of exemplary organic peroxides, the first three organic peroxides in the table having 10 hour half-life decomposition temperatures suitable for use in the present invention.

"Half-life" is a convenient way of expressing the rate of decomposition of an organic peroxide at a particular temperature. The time required for half of the organic peroxide originally present to decompose at any particular temperature is measured. These time measurements can be performed at several temperatures. Plotting the resulting data on logarithmic paper as half-life in units of time versus temperature yields a straight line. From this line it is possible to interpolate the temperature at which half of a given organic peroxide decomposes in 10 hours. This is known as the 10:00 half-life decomposition temperature.

It is recognized in the art that the exact 10 hour decomposition half-life temperature of an organic peroxide can vary somewhat depending on the test conditions used. For example, the solvent system used and the concentration of the organic peroxide can have a relatively small effect on the measured 10-hour decomposition half-life temperature. As used herein, the 10-hour decomposition half-life temperature of an organic peroxide is the 10-hour decomposition half-life temperature as reported in the following literature: "Peroxide Vulcanization of Elastomers", P. R. Dluzneski, Rubber Chemistry and Technology, vol. 74 (2001), pp. 451-492. If the 10-hour decomposition half-life temperature of a particular organic peroxide is not described in the aforementioned literature, the 10-hour decomposition half-life temperature is determined by adding the organic peroxide at a concentration of 0.1 mol/L in monochlorobenzene. 10-hour half-life decomposition temperature measured using

According to certain embodiments, the peroxide system present in the curable low sulfur liquid rubber composition consists of one or more organic peroxides having a 10 hour decomposition half-life temperature of 60°C to 100°C. (ie, the curable low-sulfur liquid rubber composition does not contain organic peroxides other than one or more organic peroxides having a 10 hour decomposition half-life temperature of 60° C. to 100° C.). In one embodiment, the peroxide system is a peroxyketal (eg, 1,1′-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane, or di(tert-butylperoxy)-cyclohexane), at least one selected from the group consisting of diacyl peroxide (e.g., dibenzoyl peroxide or dilauroyl peroxide) and peroxyesters (e.g., tert-butylperoxyisobutyrate or tert-amylperoxy-2-ethylhexyl carbonate); containing one peroxide. In another embodiment, the peroxide system is a peroxyketal (eg, 1,1′-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane, or di(tert-butylperoxy)-cyclohexane) , diacyl peroxide (eg, dibenzoyl peroxide), and peroxyesters.

The peroxide system can contain two or more organic peroxides. For example, peroxide systems include peroxyketals (eg, 1,1′-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane, or di(tert-butylperoxy)-cyclohexane), diacyl peroxide (e.g. dibenzoyl peroxide or dilauroyl peroxide) and peroxyesters (e.g. tert-butylperoxyisobutyrate or tert-amylperoxy-2-ethylhexyl carbonate). can contain things. Preferably, the two or more peroxides of the peroxide system are 1,1′-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1′-di(tert-butylperoxy) )-cyclohexane, and dibenzoyl peroxide.

The amount of peroxide system present in the curable low sulfur liquid rubber composition will depend on the type of peroxide used, the reactivity of the polymer, the type and reactivity of co-agents (if present), and the required It will vary depending on the cure properties and properties of the target cured rubber, as well as other factors. Typically, however, curable low sulfur liquid rubber compositions may contain the peroxide system in amounts of 1 to 14 phr. As used herein, the term "phr" means parts by weight per 100 parts resin, where resin is a reactive polymer (e.g., liquid polymer) present in the curable low sulfur rubber composition. polybutadiene polymer), or a combination of reactive (crosslinkable) polymers.

The curable low-sulfur liquid rubber composition may contain at least one auxiliary agent other than sulfur or a sulfur compound suitable for crosslinking. Coagents can contain one or more sites of ethylenic unsaturation (carbon-carbon double bonds) per molecule and consist of acrylates, methacrylates, bismaleimides, vinyl esters, allyl compounds, and derivatives thereof. can be selected from the group. In a preferred embodiment of the invention, the curable low sulfur liquid rubber composition comprises 0 phr to 30 phr total coagents. In another embodiment, the low sulfur liquid rubber composition may contain 0.5 to 15 weight percent coagent. However, in one embodiment, a suitable cure is a low sulfur content, e.g., less than 15 wt.%, less than 10 wt.%, less than 5 wt.%, less than 1 wt. It can be obtained as an additive for accelerating the curing of liquid rubber compositions. Advantageously, the curable low-sulfur liquid rubber composition has a sulfur content of 0-3% by weight. Preferably, the sulfur content of the low sulfur liquid rubber composition is 0-0.9 wt%, more preferably 0-0.75 wt%, more preferably 0-0.6 wt%. , or more preferably 0 to 0.5% by weight.

The curable low sulfur liquid rubber composition is adapted to be curable at temperatures of 150°C or less. For example, the curable low sulfur liquid rubber composition may be heated to a temperature of 100° C. to 150° C. for up to 2 hours to have the optimum crosslink density. For example, the low-sulfur liquid rubber composition has an optimum crosslink density at a temperature range of 100°C to 140°C, such as 105°C to 135°C, 110°C to 130°C, or 115-125°C. May be heated for 2 hours or less. Additionally or alternatively, the curable low-sulfur liquid rubber composition is heated at 100° C. to 150° C. until the cured rubber composition has a torsional shear differential of 6 dNm or more (e.g., measured as a change in torque of 6 dNm or more). can be cured by heating the liquid rubber composition for up to 2 hours at a temperature of . For example, the curable low-sulfur liquid rubber composition is heated in a temperature range of 100° C. to 140° C., 105° C. to 135° C., 110° C. to 130° C., or 115° C. to 125° C. for 2 hours or less. may be cured to have a torsional shear force differential of 6 dNm or more. In one embodiment, the curable low sulfur liquid rubber composition is cured to have a torsional shear force differential of 8 dNm or more by heating the liquid rubber composition to a temperature in the above range for 2 hours or less. good too. In another embodiment, the curable low sulfur liquid rubber composition is cured to have a torsional shear force differential of 12 dNm or more by heating the liquid rubber composition to a temperature in the above range for 2 hours or less. may

The degree of cross-linking achieved by formulations based on at least one liquid rubber resin can be estimated using a rotorless torsional shear rheometer according to known state-of-the-art techniques. Such devices measure the force generated by the deformation resistance of the sample during the cross-linking reaction of the sample. This force is measured as torque (unit: dNm). The difference in torque calculated from data provided by a rotorless torsional shear rheometer is approximately proportional to the crosslink density of the liquid rubber composition.

According to another aspect of the invention, a method is provided for making a curable low sulfur liquid rubber composition. The method polymerizes at least one monomer having a carbon chain of 4 carbon atoms to produce a polymer having a vinyl content of 1% to 90% and a number average molecular weight of 800 g/mol to 15,000 g/mol. can include doing Alternatively, suitable polymers are commercially available from companies such as Total Cray Valley™.

Additionally, the method includes combining the produced/obtained polymer with a peroxide system to prepare a curable low-sulfur liquid composition. The peroxide system includes at least one organic peroxide having a 10-hour decomposition half-life temperature in the range of 60°C to 100°C, as described above. Desirably, the curable low sulfur liquid rubber composition is curable at a temperature of 100° C. to 140° C. and has a sulfur content of 0 to 1% by weight. Additives and adjuvants can be incorporated into the curable low-sulfur liquid composition as discussed herein using processing steps known to those skilled in the art.

According to a further aspect of the invention, a cured low sulfur rubber is provided. The cured low sulfur rubber is obtained by curing the curable low sulfur liquid rubber composition by heating the curable low sulfur liquid rubber composition as disclosed herein. The curable low sulfur liquid rubber composition is advantageously curable at temperatures of 100° C. to 140° C. and has a sulfur content of 0 to 1% by weight. As a result of such curing, the curable low-sulfur liquid rubber composition is converted (eg, by a cross-linking reaction) into a solid elastomeric (rubber-like) composition. Curing is typically accomplished by heating the curable low sulfur liquid rubber composition to a temperature effective to initiate the desired cross-linking reaction involving at least the polymer component.

Optionally, one or more of Additional ingredients may be included. An illustrative list of such optional additional ingredients follows:
- one or more solid rubbers or solid elastomers;
- Fillers, preferably heat treated or treated with silanes, resins or cationic species to prevent/reduce decomposition of some peroxides;
- tackifiers and/or coupling agents;
- adhesion promoters such as functionalized liquid rubber resins (e.g. maleated liquid polybutadiene resins);
- plasticizers or extender oils, such as paraffin oil; and/or - stabilizers against heat, thermal oxidation and/or ozone degradation.

According to a particular embodiment of the invention, the curable low sulfur liquid rubber composition comprises at least one filler, in particular at least one inorganic filler. Suitable fillers include any filler known in the art for curable liquid rubber compositions, such as calcium carbonate, silica, carbon black, clay, talc, mica, calcium oxide, alumina, carbonate Magnesium etc. are mentioned. The aforementioned fillers can be heat treated or treated with silanes, resins, or cationic species to prevent or reduce decomposition of some peroxides. A curable low sulfur liquid rubber composition can contain, for example, up to 75 phr of filler.

The cured crosslinked low sulfur rubber is preferably a similar crosslinked sulfur cured without a peroxide system using an amount of sulfur or sulfur compounds effective to provide a sulfur content of greater than 1% by weight. It has a torsional shear strength at least 2.0 dNm greater than rubber. In one embodiment, the cured crosslinked low sulfur rubber is preferably cured without a peroxide system using an amount of sulfur or sulfur compounds effective to provide a sulfur content of greater than 1% by weight. , has a torque difference of at least 6.0 dNm greater than that of similar crosslinked sulfur rubbers. In another embodiment, the cured crosslinked low sulfur rubber is preferably cured without a peroxide system, using an amount of sulfur or sulfur compounds effective to provide a sulfur content of greater than 1% by weight. It has a torque difference of at least 8.0 dNm greater than similar crosslinked sulfur rubbers. In still other embodiments, the cured crosslinked low sulfur rubber is preferably cured without a peroxide system, using an amount of sulfur or sulfur compounds effective to provide a sulfur content of greater than 1 wt%. It has a torque difference of at least 12.0 dNm greater than a cured, similar crosslinked sulfur rubber.

The curable low-sulfur liquid rubber compositions of the present invention are particularly useful in the manufacture of materials intended to reduce vibration and/or acoustic noise, such as in automotive or other vehicle applications. The curable low-sulfur liquid rubber composition in the cured state has sound dampening properties. Obtained from the curable low sulfur liquid rubber composition of the present invention using any of the art-known or conventional coating, molding, shaping, forming or impregnation methods. An article comprising cured rubber can be manufactured. For example, the curable low-sulfur liquid rubber compositions of the present invention are used in the manufacture of sound dampening parts, belts, hoses, rubber rollers, industrial products, vibration mounts, tires, etc., comprising elastomeric articles or composite articles generally comprising elastomeric parts. can be used for The use of the curable low-sulfur liquid rubber compositions of the present invention as adhesives, sealants and coating agents is also contemplated. In one embodiment, the curable low-sulfur liquid rubber composition is applied to a substrate surface (e.g., metal sheet, panel or other such component using suitable techniques such as spraying, dipping, roller coating, etc.). ) and then heated to a temperature to cure the curable low sulfur liquid rubber composition. Thus, a curable low sulfur liquid rubber composition can be formulated to have a viscosity that can be applied by spraying. For example, the curable low sulfur liquid rubber composition may be sprayable using an automated application system such as a robotic system.

Embodiments have been described herein in a manner that enables clear and concise description of the specification, but it is understood that the embodiments may be combined or separated in various ways without departing from the invention. It is intended, and this goes without saying. For example, it should be understood that all preferred features described herein are applicable to all aspects of the invention described herein.

In some embodiments, the invention herein provides basic novel features of a curable low-sulfur liquid rubber composition, a process using a curable low-sulfur liquid rubber composition, or a curable low-sulfur liquid rubber composition. It can be interpreted as excluding elements or process steps that do not materially affect the article made using the composition. Additionally, in some embodiments, the invention may be construed to exclude any element or process step not specified herein.

Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention.

The following non-limiting examples are provided for the purpose of illustrating the advantages that can be obtained from aspects of the present invention.

<Example 1>
The liquid rubber composition contains sulfur or a sulfur-containing compound (e.g., in an amount greater than 4% of the total weight of the composition) that acts as a cross-linking agent; accelerators and/or super-accelerators (e.g., , an amount of 1.0% to 7.0% of the total weight of the formulation); and an activator system (eg, a ZnO/stearate compound). The total amount of sulfur and accelerators in the liquid rubber composition is generally greater than 5 weight percent. Table 2, shown below, provides typical formulations for vulcanizing liquid rubber compositions. TBBS is N-tert-butyl-2-benzothiazylsulfenamide and TMTD is tetramethylthiuram disulfide.

Table 3 below shows various RICON® polymers, which are low molecular weight homopolymers of butadiene and copolymers of butadiene and styrene monomers, manufactured by Total Cray Valley™.

A dynamic mechanical viscoelastic tester such as Alphatechnologies' Premier™ RPA was used to determine the vulcanization rate and estimate the crosslink density of the liquid rubber composition at two different temperatures (see Figures 1 and 2). bottom. Such rheometers measure the force generated by the specimen's resistance to deformation during the crosslinking reaction of the specimen. This force is measured as torque (unit: dNm). The torque difference calculated from data provided by a rotorless torsional shear rheometer is approximately proportional to the crosslink density of the liquid rubber composition.

By using large amounts of sulfur and accelerator (e.g., greater than 10 wt% sulfur and accelerator), liquid styrene-butadiene copolymers and liquid polybutadiene were crosslinked at temperatures between 140°C and 160°C. . However, the crosslink density of all cured rubber compositions remained low (eg, as indicated by torque values less than 8 dNm) in this cure temperature range.

<Example 2>
The Premier™ RPA instrument described above was used to evaluate the crosslink density of several RICON® polymers using peroxide systems, including organic peroxides. Curable low sulfur liquid rubber compositions containing RICON® 131 polymer were cured with the peroxide systems shown in Table 4. The crosslink density of the low sulfur liquid rubber composition, as determined by torsional shear force, was evaluated and shown graphically in FIG.

The 1,2-vinyl group content of the RICON® 131 polymer was less than 35%. As shown in Figure 3, low sulfur liquid rubber compositions containing RICON® 131 were not highly reactive with standard organic peroxides. However, the three peroxide systems were shown to provide higher crosslink densities than vulcanization systems containing sulfur. Furthermore, the amount of cross-linking agent used to cure liquid rubber compositions containing RICON® 131 with peroxide systems is significantly reduced, for example by about 26%, to achieve high cross-linking levels. did not require an accelerator. A peroxide system containing two organic peroxides was very effective in curing low sulfur liquid rubber compositions containing RICON® 131 at temperatures up to 140°C. Furthermore, the peroxide system using two organic peroxides produced the highest amount of cross-linking.

<Example 3>
A liquid rubber composition containing the RICON® 156 polymer was subjected to a peroxide system or vulcanization test to determine if the liquid rubber composition could be cured at a temperature of 130°C using a peroxide system. Cured using either system. Table 5 below provides details of the liquid rubber compositions tested in this example.

As shown in Figure 4, the crosslink density of the rubber composition cured at a temperature of 140°C with a sulfur-based vulcanization system is higher than that of the low sulfur rubber composition cured with a peroxide system at a temperature of 130°C. was much lower than the crosslink density of Further, the amount of products involved during curing of low sulfur rubber compositions with peroxide systems is compared to the amount of products involved during curing of rubber compositions with sulfur based vulcanization systems. and decreased significantly (eg, by more than 50%).

<Example 4>
Liquid rubber compositions containing RICON® 142 polymer were cured using a peroxide system or a vulcanization system to evaluate the crosslink density produced by curing liquid rubber compositions with high vinyl content. . RICON® 142 polymer has a vinyl content of about 55%. Liquid rubber compositions containing RICON® 142 are shown in Table 6. FIG. 5 shows a graph comparing the crosslink density (as indicated by the measured torque difference) during curing of rubber compositions containing RICON® 142 polymer.

Curing a liquid rubber composition having a vinyl content of about 55% and comprising RICON® 142 with a peroxide system yields a rubber composition cured with a sulfur-based vulcanization system. It has been found to produce cured rubber compositions having significantly greater crosslink densities in comparison. By combining 1,1-di(t-butylperoxy)-cyclohexane with di(t-butylperoxy)-cyclohexane, while reducing the amount of chemicals used for curing by more than 3.5 times. , the crosslink density of the cured rubber composition increased by a factor of 3 (compared to the standard vulcanization system).

<Example 5>
Liquid rubber compositions containing RICON® 150 or RICON® 100 are cured with peroxide systems or sulfur-based vulcanization systems, compared to sulfur-based vulcanization systems. was evaluated for the crosslink density produced by the peroxide system. The formulations of the liquid rubber compositions are provided in Table 7 and a graph comparing the crosslink density during curing of the liquid rubber compositions is provided in FIG.

Advantageously, a peroxide system and a liquid polybutadiene with a high vinyl content (eg RICON® 150) or a styrene-butadiene copolymer with a high vinyl content (eg RICON® 100) high crosslink density and significantly reduced amount of crosslinker (approximately 70% less crosslinker compared to similar rubber compositions cured using sulfur-based vulcanization systems) by using was observed to result in a cured low sulfur rubber composition having a These results were observed at curing temperatures of 120°C and 130°C.

<Example 6>
Further investigation of curable compositions based on liquid rubber resins and peroxide systems was carried out to further improve their cure speed (compared to sulfur vulcanization systems). Below are examples of compositions based on liquid rubber resins and cured at 140° C. (with both types of crosslinking systems):
Liquid rubber compositions were cured at 140° C. with a peroxide system or a sulfur-based vulcanization system and compared to the effects of curing with a preferred peroxide system. Table 8 provides the formulation of the liquid rubber composition.

The low sulfur rubber composition cured by the peroxide system had a hardness and cure time approximately equal to the hardness and cure time of the rubber composition cured by the sulfur based vulcanization system. However, the low sulfur rubber composition cured by the peroxide system advantageously contained 38% less crosslinker than the rubber composition cured by the sulfur based vulcanization system.
The disclosure further includes the following aspects:
<<Aspect 1>>
A polymer comprising in polymerized form at least one monomer having a carbon chain of 4 carbon atoms, said polymer having a vinyl content of 1% to 90% and a number average molecular weight of 800 g/mol to 15,000 g/mol. a polymer having
a peroxide system comprising at least one organic peroxide having a 10 hour decomposition half-life temperature of 60°C to 100°C;
A curable low-sulfur liquid rubber composition comprising
A composition, wherein said composition has a sulfur content of 0-1% by weight and is curable at a temperature of 100°C to 140°C.
<<Aspect 2>>
The composition of aspect 1, wherein the polymer comprises butadiene in polymerized form.
<<Aspect 3>>
The composition of aspect 1, wherein the polymer comprises butadiene and styrene in polymerized form.
<<Aspect 4>>
The composition of aspect 1, wherein the polymer comprises at least one of liquid polybutadiene and liquid styrene-butadiene copolymer and has a 1,2-vinyl content of at least 10%.
<<Aspect 5>>
A composition according to aspect 1, wherein the at least one peroxide is selected from the group consisting of peroxyketals, diacyl peroxides, and peroxyesters.
<<Aspect 6>>
A composition according to aspect 1, wherein the peroxide system comprises at least two organic peroxides.
<<Aspect 7>>
7. The composition of aspect 6, wherein the at least two organic peroxides are selected from the group consisting of peroxyketals, diacyl peroxides, and peroxyesters.
<<Aspect 8>>
the at least two peroxides are 1,1′-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1′-di(tert-butylperoxy)-cyclohexane, and dibenzoyl peroxide A composition according to aspect 5, selected from the group consisting of:
<<Aspect 9>>
A composition according to aspect 1, wherein the composition further comprises from 0.5% to 15% by weight of at least one auxiliary agent, other than sulfur or a sulfur compound, suitable for crosslinking.
<<Aspect 10>>
10. The composition of aspect 9, wherein the at least one coagent is selected from the group consisting of acrylates, methacrylates, bismaleimides, vinyl esters, allyl compounds, and derivatives thereof.
<<Aspect 11>>
The composition according to aspect 1, wherein said composition is curable at a temperature of 110°C to 140°C.
<<Aspect 12>>
The composition according to aspect 11, wherein said composition is curable at a temperature of 120°C to 140°C.
<<Aspect 13>>
A composition according to aspect 1, wherein said composition further comprises additives or auxiliaries suitable for facilitating curing of said composition.
<<Aspect 14>>
A composition according to aspect 1, wherein the composition is free of mineral oil or aromatic oil.
<<Aspect 15>>
A crosslinked low sulfur rubber comprising the composition of aspect 1 cured at a temperature of 100°C to 140°C.
<<Aspect 16>>
The cured crosslinked low sulfur rubber uses an effective amount of sulfur or sulfur compounds to provide a sulfur content of greater than 1 wt. 16. Crosslinked low sulfur rubber according to aspect 15, having a torsional shear differential greater than 2.0 dNm.
<<Aspect 17>>
curing the curable low-sulfur liquid rubber composition according to aspect 1 by heating;
wherein the curable low sulfur liquid rubber composition is curable at a temperature of 100° C. to 140° C. and contains 0 to 1 wt. How to have quantity.
<<Aspect 18>>
polymerizing at least one monomer having a carbon chain of 4 carbon atoms to produce a polymer having a vinyl content of 1% to 90% and a number average molecular weight of 800 g/mol to 15,000 g/mol; as well as
preparing a curable low sulfur liquid rubber composition based on the resulting polymer and peroxide system;
wherein the peroxide system comprises at least one organic peroxide having a 10-hour decomposition half-life temperature of 60°C to 100°C, wherein Said curable low sulfur liquid rubber composition is curable at a temperature of 100° C. to 140° C. and has a sulfur content of 0 to 1% by weight.

Claims (13)

A polymer comprising in polymerized form at least one monomer having a carbon chain of 4 carbon atoms, said polymer having a vinyl content of 1% to 90% and a number average molecular weight of 800 g/mol to 15,000 g/mol. a polymer having
1,1′-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1′-di(tert-butylperoxy), has a 10-hour decomposition half-life temperature of 60° C. to 100° C. )-cyclohexane, and a peroxide system comprising at least two organic peroxides selected from the group consisting of dibenzoyl peroxide;
A curable low-sulfur liquid rubber composition comprising
said composition having a sulfur content of 0-1% by weight and being curable at a temperature of 100° C.-140° C .;
wherein the polymer comprises butadiene in polymerized form;
Composition. 2. The composition of claim 1, wherein the polymer comprises butadiene and styrene in polymerized form. The composition of claim 1, wherein said polymer comprises at least one of liquid polybutadiene and liquid styrene-butadiene copolymer and has a 1,2-vinyl content of at least 10%. A composition according to claim 1, wherein the composition further comprises from 0.5% to 15% by weight of at least one auxiliary agent other than sulfur or a sulfur compound suitable for crosslinking. 5. The composition of Claim 4 , wherein said at least one coagent is selected from the group consisting of acrylates, methacrylates, bismaleimides, vinyl esters, allyl compounds, and derivatives thereof. A composition according to claim 1, wherein said composition is curable at a temperature of 110°C to 140°C. A composition according to claim 6 , wherein said composition is curable at a temperature of 120°C to 140°C. 2. The composition of claim 1, wherein said composition further comprises additives or auxiliaries suitable for accelerating curing of said composition. 2. The composition of claim 1, wherein said composition does not contain mineral oil or aromatic oil. A crosslinked low sulfur rubber comprising the composition of claim 1 cured at a temperature of 100°C to 140°C. The cured crosslinked low sulfur rubber uses an effective amount of sulfur or sulfur compounds to provide a sulfur content of greater than 1 wt. Crosslinked low sulfur rubber according to claim 10 , having a torsional shear differential greater than 2.0 dNm. curing the curable low-sulfur liquid rubber composition of claim 1 by heating;
wherein the curable low sulfur liquid rubber composition is curable at a temperature of 100° C. to 140° C. and contains 0 to 1 wt. How to have quantity. polymerizing at least one monomer having a carbon chain of 4 carbon atoms to produce a polymer having a vinyl content of 1% to 90% and a number average molecular weight of 800 g/mol to 15,000 g/mol; and preparing a curable low sulfur liquid rubber composition based on the resulting polymer and peroxide system;
A method for producing a crosslinked low sulfur rubber comprising
The peroxide system has a 10-hour decomposition half-life temperature of 60° C. to 100° C. and 1,1′-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1′ -di(tert-butylperoxy)-cyclohexane, and at least two organic peroxides selected from the group consisting of dibenzoyl peroxide;
wherein said curable low sulfur liquid rubber composition is curable at a temperature of 100° C. to 140° C. and has a sulfur content of 0 to 1% by weight;
wherein the polymer comprises butadiene in polymerized form;
Method.

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